Plain English Meaning

A chart that shows how much power the engine has to produce to keep the airplane flying level at any given speed. Both very slow flight and very fast flight need a lot of power; somewhere in the middle is the speed where the airplane needs the least.

Full Definition

A graph showing how much engine power an airplane needs to maintain level flight at each airspeed. The curve is U-shaped: power required is high at very slow speeds, drops to a minimum at a specific speed, then rises again as speed increases. The low point of the curve marks the airspeed at which the airplane flies most efficiently in terms of power.

Context Anchor

Seen in discussions of slow flight, elevator use, and why an airplane may need more power to when it is flown slower.